An eclectic essayist is necessarily a dilettante, which is not in itself a bad thing. But Gladwell frequently holds forth about statistics and psychology, and his lack of technical grounding in these subjects can be jarring. He provides misleading definitions of “homology,” “sagittal plane” and “power law” and quotes an expert speaking about an “igon value” (that’s eigenvalue, a basic concept in linear algebra). In the spirit of Gladwell, who likes to give portentous names to his aperçus, I will call this the Igon Value Problem: when a writer’s education on a topic consists in interviewing an expert, he is apt to offer generalizations that are banal, obtuse or flat wrong.

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The common thread in Gladwell’s writing is a kind of populism, which seeks to undermine the ideals of talent, intelligence and analytical prowess in favor of luck, opportunity, experience and intuition. ….Unfortunately he wildly overstates his empirical case. It is simply not true that a quarter­back’s rank in the draft is uncorrelated with his success in the pros, that cognitive skills don’t predict a teacher’s effectiveness, that intelligence scores are poorly related to job performance or (the major claim in “Outliers”) that above a minimum I.Q. of 120, higher intelligence does not bring greater intellectual achievements.

The reasoning in “Outliers,” which consists of cherry-picked anecdotes, post-hoc sophistry and false dichotomies, had me gnawing on my Kindle. Fortunately for “What the Dog Saw,” the essay format is a better showcase for Gladwell’s talents, because the constraints of length and editors yield a higher ratio of fact to fancy. Readers have much to learn from Gladwell the journalist and essayist. But when it comes to Gladwell the social scientist, they should watch out for those igon values.